R/grass_i_pca.R

In JanCaha/r_package_qgis: An extension of package "qgisprocess" providing direct R functions for QGIS functions

##' QGIS Algorithm provided by GRASS i.pca (grass:i.pca). Principal components analysis (PCA) for image processing.
##'
##' @title QGIS algorithm - i.pca
##'
##' @param input `multilayer` - Name of two or more input raster maps. .
##' @param rescale `range` - Rescaling range for output maps. For no rescaling use 0,0. Two comma separated numeric values, e.g. '1,10'.
##' @param percent `number` - Cumulative percent importance for filtering. A numeric value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.
##' @param .n `boolean` - Normalize (center and scale) input maps. 1 for true/yes. 0 for false/no. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression. Original algorithm parameter name: -n.
##' @param .f `boolean` - Output will be filtered input bands. 1 for true/yes. 0 for false/no. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression. Original algorithm parameter name: -f.
##' @param output `folderDestination` - Output Directory. Path for an existing or new folder.
##' @param GRASS_REGION_PARAMETER `extent` - GRASS GIS region extent. A comma delimited string of x min, x max, y min, y max. E.g. '4,10,101,105'. Path to a layer. The extent of the layer is used..
##' @param GRASS_REGION_CELLSIZE_PARAMETER `number` - GRASS GIS region cellsize (leave 0 for default). A numeric value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.
##' @param ... further parameters passed to `qgisprocess::qgis_run_algorithm()`
##' @param .complete_output logical specifying if complete out of `qgisprocess::qgis_run_algorithm()` should be used (`TRUE`) or first output (most likely the main) should read (`FALSE`). Default value is `TRUE`.
##' @param .quiet logical specifying if parameter `.quiet` for `qgisprocess::qgis_run_algorithm()` Default value is `TRUE`.
##' @param .messages logical specifying if messages from `qgisprocess::qgis_run_algorithm()` should be printed (`TRUE`) or not (`FALSE`). Default value is `FALSE`.
##'
##' @details
##' ## Outputs description
##' * output - outputFolder - Output Directory
##'
##'
##' @export
##' @md
##' @importFrom qgisprocess qgis_run_algorithm

grass_i_pca <- function(input = qgisprocess:::qgis_default_value(), rescale = qgisprocess:::qgis_default_value(), percent = qgisprocess:::qgis_default_value(), .n = qgisprocess:::qgis_default_value(), .f = qgisprocess:::qgis_default_value(), output = qgisprocess:::qgis_default_value(), GRASS_REGION_PARAMETER = qgisprocess:::qgis_default_value(), GRASS_REGION_CELLSIZE_PARAMETER = qgisprocess:::qgis_default_value(),..., .complete_output = .complete_output_option(), .quiet = .quiet_option(), .messages = .message_option()) {

  check_algorithm_necessities("grass:i.pca")

  if (.messages){
    output <- qgisprocess::qgis_run_algorithm("grass:i.pca", `input` = input, `rescale` = rescale, `percent` = percent, `-n` = .n, `-f` = .f, `output` = output, `GRASS_REGION_PARAMETER` = GRASS_REGION_PARAMETER, `GRASS_REGION_CELLSIZE_PARAMETER` = GRASS_REGION_CELLSIZE_PARAMETER,..., .quiet = .quiet)
  } else {
    suppressMessages(
      output <- qgisprocess::qgis_run_algorithm("grass:i.pca", `input` = input, `rescale` = rescale, `percent` = percent, `-n` = .n, `-f` = .f, `output` = output, `GRASS_REGION_PARAMETER` = GRASS_REGION_PARAMETER, `GRASS_REGION_CELLSIZE_PARAMETER` = GRASS_REGION_CELLSIZE_PARAMETER,..., .quiet = .quiet)
      )
  }

  if (.complete_output) {
    return(output)
  }
  else{
    qgisprocess::qgis_extract_output(output, "output")
  }
}